Method of making a protective sheath for boat hulls



A. J. HUSTON 3,143,453

METHOD OF MAKING A PROTECTIVE SHEATH FOR BOAT HULLS Aug. 4, 1964 FiledNov. 14, 1962 FIG I FIGSlllllllllllIlllllllllllllllHllllllllllllllllllllllllllllllllllg/HIIIIHHIIll"llllllIHIIIIIIIIIIIIIIIllllllllllll FIG-5 FIG.I4

FIGJZ United States Patent 3,143,453 METHOD 9F MAKING A PROTECTIVESHEATH FGR BOAT HULLS Albert J. Heston, 5125 Benton St., Lincoln, Nebr.Filed Nov. 14, 1962, Ser. No. 237,469 Claims. (Cl. 156267) Thisinvention generally relates to protective sheaths for waterborneobjects. More particularly, this invention relates to a method forproducing a protective covering (e.g. a hull sheath) to be applied to aboat hull by means of its elastic and gripping properties.

It is well known that boat hulls may be constructed of an almostunlimited variation of materials so long as waterproof characteristicsare present. A boat or buoy may often be subjected to adverse weatherconditions or to corrosive action by mineral components or detrimentalorganisms in the water. In operation, a boat may also become damaged byobjects floating on the water or by inadvertent contact with dockingfacilities or piers, thus damaging the hull. Other occasions whichpresent possible damage to a boat hull are encountered when it has beenremoved from the water for transportation or storage purposes.

This invention has as its primary object the provision of a method forforming a protective sheath to reduce the effect of hazards which wouldordinarily damage a boat hull. A sheath made in accordance with thisinvention may be applied to most conventional hull structures.

Another object of this invention is to provide a method of applying aprotective sheath to any waterborne object having a form which may beassumed by the deformation of an elastic sheet.

A further object of the present invention is the provision of an easilyformed, inexpensive and versatile fabrication operation for theformation of a protective sheath.

Another object of the present invention is the provision of a protectivesheath which may be formed without special equipment, such as preformedmolding devices.

Another object of this invention is the provision of a protective sheathfor boat huils which will prevent side slip and reduce surface drag.

Another object is the provision of a protective sheath which will giveyear-round protection for a hull stored either in or out of the waterand which can be easily repaired if damaged.

These and other objects and advantages may be achieved by the inventiondescribed hereinafter when read in conjunction with the drawings,wherein:

FIGURE 1 is a side view of a half hull fabric pattern;

FIGURE 2 is a cross-sectional view along 22 of FIG- URE 1;

FIGURE 3 is a side view showing the fabric pattern of FIGURE I placedupon a first sheet of elastic waterproof material;

FIGURE 4 is a cross-sectional view along 44 of FIG- URE 3;

FIGURE 5 is a side view showing the arrangement of FIGURE 3 with addedborder strips;

FIGURE 6 is a cross-sectional view along 6-6 of FIGURE 5;

FIGURE 7 is a side view showing the arrangement of FIGURE 5 after theapplication of an overlying sheet of elastic waterproof material;

FIGURE 8 is an end view of FIGURE 7;

FIGURE 9 is a side view showing the arrangement of FIGURE 7 aftertrimming;

FIGURE 10 is a cross-sectional view along 1t)10 of FIGURE 9;

FIGURES 11 and 12 are sequential views similar to FIGURE 10 showing howthe fabric pattern is removable;

FIGURE 13 is a perspective view of a hull sheath in accordance with thisinvention;

FIGURE 14 is an enlarged fragmentary view of FIG- URE 11 showing theshape of the inner faces of the outer sheets after being separated fromthe fabric pattern.

In one of its broader aspects the present invention can be considered ascomprising the following procedural steps (and the product producedthereby) (1) Providing a half-hull pattern which has dimensionscorresponding to the dimensions of approximately the surface area of ahull which is on either half of a vertical plane passing midway throughthe bow and stern,

(2) Said pattern preferably being made from a fabric having a limiteddegree of porosity,

(3) Placing said half-hull pattern upon a first sheet made of elastic,waterproof material,

(4) Said first sheet having length, width and heighth, dimensions whichexceed the corresponding dimensions of said half-hull pattern;

(5) Placing a comparatively narrow border strip of material around thefront, rear and bottom sides of said half-hull pattern,

(6) Placing a second sheet on said half-hull pattern and border strip,said second sheet being the same size and composition as said firstsheet,

(7) subjecting the aforesaid assembly to a bonding operation so that thefacing surfaces of said first sheet, second sheet and border strip bondtogether,

(8) Trimming the front, rear and bottom sides of said assembly to thedesired degree,

(9) Trimming the top of said assembly along a line correspondinggenerally with the top line of said half-hull pattern and removing saidhalf-hull pattern from between said first and second sheets.

The step of cutting the half-hull pattern to the dimension of one halfof the boat to be covered is not absolutely critical but the closer oneapproximates the exact dimensions of one-half the surface area of thehull the better will be the fit of the end product.

Referring now to FIGURE 1, the half-hull pattern 20, which is generallydefined by points A, B, C and D, may be made of a number of differentmaterials. Loosely woven textile fabrics having square openings havebeen found preferable. The size and shape of the pores or openings inthe pattern, as well as the thickness of the pattern material willgovern or at least largely influence the type of interior surface thatthe final product (hull sheath) will have.

The front and rear planar surfaces of the half-hull pattern 20 arepreferably treated with a material which will either minimize orcompletely eliminate the bonding of the half-hull pattern to sheets ofelastic, waterproof material. For example, the half-hull pattern can bedusted with soapstone or sprayed with a silicone mold release lubricant.

The treated half-hull fabric pattern 20 is then placed upon a firstsheet of elastic, waterproof material 30 (having the boundaries E, F. G,H), and as is shown in FIG URE 3 the half-hull fabric pattern 20 onlypartially covers said sheet 3%]. The elastic sheet material 30 ispreferably composed of uncured gum rubber, either natural or synthetic.The sheet 30 should be sufiiciently large so that portions of the sheet30 extend outwardly beyond the periphery of the half-hull fabric pattern20 as shown in FIGURE 1. A satisfactory result has been obtained byutilizing a sheet 30 which extends outwardly at least one foot from allsides of the half-hull fabric pattern 20 but a lesser distance issatisfactory where economy of materials is quite important.

One or more strips of border material 50, made of uncured rubber andhaving the same bondable properties as said first sheet 30 are placedaround a portion of the 3 outer periphery of the half-hull fabricpattern at a location outside of points A, B, C, D and within the areadefined by points E, F, G and H (see FIGURES 5 and 6). A strip 50 aboutone foot wide will usually sufiice.

A second sheet of elastic waterproof material 4! having the samedimensions as the first sheet 30 is then placed over the previouslydescribed assembly to thus produce the arrangement shown in FIGURES 7and 8. The resulting assembly is thus seen to be composed of said firstsheet 30, the fabric pattern 20, partly surrounded by the bordermaterial 50, and said second sheet 40. The raised outline of the fabricpattern (and contiguous border strips) are usually quite visible (e.g.see FIGURE 7) but in the event the outline is not readily visible theoutline may be traced with a non-curing marking crayon to aid in thelater step of removing the fabric pattern. Such a line is drawn tooutline the extended keel portions. The upper line is drawn even withthe top of the fabric pattern. The assembly shown in FIGURES 7 and 8 isthen cured by conventional means including heat and pressure. An openside press has been found to satisfactorily perform this curing step.However, other curing methods may be used. The fact that the assembly isin substantially a single plane during the curing process precludes thenecessity for elaborate molding equipment for the production of a hullsheath. When the curing step has been completed at a suitable pressureand temperature the assembly is removed from the press and allowed tocool. It should be noted that the inner faces of the sheets 30 and 40and the intermediate border strip 59 will be firmly bonded together tothus form a bonded laminar construction completely surrounding thefabric pattern 20. The fabric patern 20 interposed between the sheets 30and 40 serves to prevent the portions of sheets 30 and 40 which abutdirectly against the fabric pattern from bonding together. An impressionof the fabric pattern 20 will be formed on portions of the inner facesof the sheets 30 and 40 due to the weave of the fabric.

The cured assembly is then trimmed to the desired size by cutting eitheralong a visible ridge or along a line marked prior to the curingoperation, and a product is obtained as shown in FIGURES 9 and 10.Enough of the border portion is retained after trimming so that aftersheets 30 and 40 are spread apart and the fabric pattern 20 removed, athick laminated portion will re main corresponding to the keel. Cuttingaway all but about A; inch of the border strip 50 has been found toproduce a quite satisfactory product, but wider strips can be left ifdesired. However, the width of the laminated bonding portion (containingthe border strip) that is allowed to remain need not be uniform alongthe length of the keel. A portion along the bottom of the boat mayadvantageously be allowed to extend six inches to eighteen inches. Thisextending portion will act to prevent side slip in a similar manner tothe extended keel of a sailboat. Even when this keel effect is desiredit is preferable to have the bow and stem portions trimmed down to amuch narrower width (e.g. one-eighth inch). In a preferred embodiment ofthis invention the bow and stern seam portions (containing the borderstrip) of the hull sheath are closely trimmed to approximately inch andthe bottom seam keel portion allowed to extend 6 to 18 inches. The topof the product shown in FIGURE 7 has been out along a line correspondingwith the upper edge of the fabric pattern 20 so that the sheets 30 and40 can be spread apart to expose the fabric pattern 20.

While the fabric pattern 20 performs an important function in theformation of the hull sheath it must be removed from the product shownin FIGURES 9, 10 and 11. Since the fabric pattern 20 and the sheets 30and 44) are only loosely bonded together (if at all) due to the presenceof the soapstone or silicone mold release lubricant, the sheets 30 and49 may be easily separated and the fabric pattern removed. The steps ofremoval are best illustrated in FIGURES 11 and 12, wherein the sheets3t) and 40 are shown separated from the interposed fabric pattern 20. Asrubber sheets 30 and 40 are separated and the fabric pattern 20 removed,it will be noticed that the fabric pattern 29 will have left animpression on the interior faces of the hull sheath. Referring now toFIG- URE 14, the small gripping edges or fingers that are formed on theinner faces of the sheets 30 and 40 are shown. These gripping edges orfingers aid in retaining the hull sheath on the boat hull. The weave ofthe fabric pattern 20 will control the size, shape and configuration ofthe gripping edges or fingers and one may easily experiment with variousfabric patterns so as to produce a surface having the desired clingingcharacteristics. Depending also upon the weave of the fabric and thepressure of the curing press the sheets 30 and 40 may even continueduntil the fabric pattern 20 may be removed compores or openings in thefabric pattern, thus resulting in portions of sheets 30 and 49 beingbonded through the openings in the fabric pattern 2%. These bondedportions will be broken during removal of the fabric pattern 20 and theinner faces of sheets 39 and 4%) will be found to have very desirablegripping features. The separation of the sheets 3% and 46 as shown inFIGURE 11 is of course continued until the fabric pattern 20 may beremoved completely. FIGURE 12 shows a cross-sectional view of the hullsheath with the fabric removed. If the fabric pattern 20 has beenproperly measured the sheets 30 and 40 will substantially conform to thehull of the boat.

The hull sheaths formed by my method may be placed on a boat by firststretching the sheet over the stern as shown, then ethe sheath may beprogressively stretched forward by the progressive stretching of the bowportion of the sheath and upward over the bow of the boat. The veryflexible and elastic properties of the sheath allows it to conform tothe shape of the boat hull. The gripping inner faces of the hull sheathretains the sheath on the boat hull in a tightly clinging relationship.

Depending upon the desired strength of the sheath and the size of theboat to be covered, various thicknesses of elastic sheet material may beused. A .062 gauge blank of elastic sheet material has been found to besufiicient for an eleven-foot boat. This method may be used to produce aprotective hull sheath for boats of all types from 5 feet to 50 feet inlength. The hull sheath may be replaced or if damaged may be easilyrepaired by conventional means.

In conclusion, while there has been illustrated and described apreferred embodiment of my invention, it is to be understood that sincethe various details of construction may obviously be varied considerablywithout really departing from the basic principles and teachings of thisinvention, I do not limit myself to the precise constructions hereindisclosed and the right is specifically reserved to encompass allchanges and modifications coming within the scope of the invention asdefined in the appended claims. Having thus described my invention, whatI claim as new and desire to secure as United States Letters Patent is:

1. A method for producing protective sheaths for boat hulls whichcomprises the steps of:

(1) providing a half-hull pattern which has dimensions corresponding tothe dimensions of approximately the surface area of a hull which is oneither half of a vertical plane passing midway through the bow andstern,

(2) said pattern preferably being made from a fabric material having alimited degree of porosity,

(3) placing said half-hull pattern upon a first sheet made of elastic,waterproof material,

(4) said first sheet having length, width and heighth, dimensions whichexceed the correspondinbg dimensions of said half-hull pattern;

(5) placing a comparatively narrow border strip of material around thefront, rear and bottom sides of said half-hull pattern,

(6) placing a second sheet over said half-hull pattern and border strip,said second sheet being about the same size and compositions as saidfirst sheet,

(7) subjecting the aforesaid assembly to a bonding operation so that thefacing surfaces of said first sheet, second sheet and border strip bondtogether,

(8) trimming the front, rear and bottom sides of said assembly to thedesired degree,

(9) trimming the top of said assembly along a line correspondinggenerally with the top line of said half-hull pattern, and

(10) removing said half-hull pattern from between said first and secondsheets so as to thereby form a protective sheath for a boat hull.

Q. A method according to claim 1 wherein half-hull pattern comprises aloosely woven textile fabric.

3. A method according to claim 2 wherein said fabric has squareopenings.

4. A method according to claim 1 wherein said pat- 5. A method accordingto claim 1 wherein said sheets 5 are made of uncured gum rubber.

References Cited in the file of this patent UNITED STATES PATENTS1,287,429 Price Dec. 10, 1918 1,934,547 Little Nov. 7, 1933 2,584,632Southwick Feb. 5, 1952 2,748,048 Russell May 29, 1956 2,898,257 CarverAug. 4, 1959 2,926,362 Collins et a1. Mar. 1, 1960 3,044,516 Stoll July17, 1962 3,055,022 Vallquist Sept. 15, 1962 3,057,580 Hahn Oct. 9, 1962

1. A METHOD FOR PRODUCING PROTECTIVE SHEATHS FOR BOAT HULLS WHICHCOMPRISES THE STEPS OF: (1) PROVIDING A HALF-HULL PATTERN WHICH HASDIMENSIONS CORRESPONDING TO THE DIMENSIONS OF APPROXIMATELY THE SURFACEAREA OF A HULL WHICH IS ON EITHER HALF OF A VERTICAL PLANE PASSINGMIDWAY THROUGH THE BOW AND STERN, (2) SAID PATTERN PREFERABLY BEING MADEFROM A FARBIC MATERIAL HAVNG A LIMITED DEGREE OF POROSITY, (3) PLACINGSAID HALF-BULL PATTERN UPON A FIRST SHEET MADE OF ELASTIC, WATERPROOFMATERIAL, (4) SAID FIRST SHEET HAVING LENGTH, WIDTH AND HEIGHTH,DIMENSIONS WHICH EXCEED THE CORRESPONDING DIMENSIONS OF SAID HALF-HULLPATTERN; (5) PLACING A COMPARATIVELY NARROW BORDER STRIP OF MATERIALAROUND THE FRONT, REAR AND BOTTOM SIDES OF SAID HALF-HULL PATTERN, (6)PLACING A SECOND SHEET OVER SAID HALF-HULL PATTERN AND BORDER STRIP,SAID SECOND SHEET BEING ABOUT THE SAME SIZE AND COMPOSITIONS AS SAIDFIRST SHEET, (7) SUBJECTING THE AFORESAID ASSEMBLY TO A BONDINGOPERATION SO THAT THE FACING SURFACES OF SAID FIRST SHEET, SECOND SHEETAND BORDER STRIP BOND TOGETHER, (8) TRIMMING THE FRONT, REAR AND BOTTOMSIDES OF SAID ASSEMBLY TO THE DESIRED DEGREE, (9) TRIMMING THE TOP OFSAID ASSEMBLY ALONG A LINE CORRESPONDING GENERALLY WITH THE TOP LINE OFSAID HALF-HULL PATTERN, AND (10) REMOVING SAID HALF-HULL PATTERN FROMBETWEEN SAID FIRST AND SECOND SHEETS SO AS TO THEREBY FORM A PROTECTIVESHEATH FOR A BOAT HULL.